Q. Have you ever heard of grapefruit juice causing an elevated blood pressure?
I have not heard of grapefruit juice per se causing high blood pressure. But there is a concern about the interaction of grapefruit juice with a number of drugs for common illnesses.
Grapefruit juice is one of the foods most likely to cause problems with drugs, because it is metabolized by the same enzyme in the liver that breaks down many drugs. The cytochrome P-450 3A4 enzyme breaks down grapefruit juice into useful components for the body, just like it breaks down dozens of medications. When the system is overloaded, the grapefruit juice can swamp the system, keeping the liver busy and blocking it from breaking down drugs and other substances.
Drugs that use the same pathway and interact with grapefruit juice target some of the most common health problems doctors see today. The list consists of more than 50 medications, including some drugs used to treat high cholesterol, depression, high blood pressure, cancer, depression, pain, impotence, and allergies.
A warning about grapefruit juice is included in the food-drug interactions that come with dozens of medications. If you have a concern that one of your medications interacts with a diet high in grapefruit juice then talk to your pharmacist or doctor.